Frequency selector



March 24, 1953 w. s. EATON FREQUENCY SELECTOR 4 Sheets-Sheet 1 Filed Sept. 8, 1947 March 24, 1953 w. s. EATON FREQUENCY SELECTOR 4 Sheets-Sheet 2 Filed Sept. 8, 1947 FIG.

FIG. 5

March 24, 1953 w. s. EATON FREQUENCY SELECTOR 4 Sheets-Sheet 5 Filed Sept. 8. 194'? fill 3nventor March 24, 1953 w. s. EATON 2,632,521 FREQUENCY SELECTOR Filed Sept. 8, 1947 4 Sheets-Sheet 4 v 3nventor WARREN S. ATON, n, d

Patented Mar. 24, 1953 UNITED STATES PATENT OFFICE FREQUENCY SELECTOR Warren S. Eaton, Los Angeles, Calif.

Application September 8, 1947, Serial No. 772,607

8 Claims.

cording to their respective rates of vibration in the'fiuid, and then selectively conveying on one or more of such separated frequencies for use or consideration.

In the present patent application the word "frequency? and the word vibration are used to mean substantially the same thing. In other words, a frequency is a rate of vibration or a vibration of a predetermined rate. Frequen cies mean a plurality of different rates of vibration or vibrations of different rates.

Another object is to provide for separating a plurality of frequencies into component frequencies and selectively passing any one or more of such components for use or consideration.

It is also anobject of the invention to provide for separating a plurality of frequencies into components, then selecting any one component, and then spreading said selection at either or opposite sides of said selected component and passing such selected components 'for use or consideration. 7

It is also proposed to utilize or incorporate the present invention in a stethoscope whereby frequencies emanating from the body of a person may be received and then separated and selectively passed for observation.

With these and other objects in view, the present invention consists in the combination and arrangement of parts as will be hereinafter more fully described, illustrated in the accompanying drawings and pointed out in the appended claims, it, of course, being understood that changes in the form, proportion, size and minor details may be made, within the scope of the claims, without departing from the spirit or sacrificing any of the advantages of the invention.

- In the drawings:

a Figure l is a longitudinal sectional view of a frequency separator and selector showing one embodiment of the present invention.

Figure 2 is a detail fragmentary sectional plan view showing the registered end portions of the valve sections with the valve openings therein in complete registration.

Figure 3 is a view similar to Figure 2 showing the complete valve turned to bring its port-into registration with a plurality of ports of thefrequency divider or separator.

2 Figure 4 is a similar view showing one of the valve sections turned to bring its port opening out of complete registration with the port of the other valve section.

Figure 5 is a fragmentary detail cross sectional view taken through a pair of registered ports 54 and 55.

Figure 6 is an enlarged detail fragmentary sectional view of one form of pressure change relief means.

Figure '7 is a fragmentary sectional view of a gauge arrangement for use in adjusting the valve of Figure 1.

Figure 8 is a longitudinal sectional view of another embodiment of the invention.

Figure 9 is a longitudinal sectional view of still another embodiment of the invention.

Figure 10 is a plan view of Figure 9, parts being broken away to show an interior construction.

Figure 11 is a detail cross sectional view on the I line II-ll of Figure 10.

Figure 12 is a detail cross sectional viewon the line l2l2 of Figure 10.

Figure 13 is a plan View showing the slots in the valve member of Figures 9 and 10.

Figures 14 and 15 are views similar to Figures 11 and 12 showing the double slot arrangement.

Figure 16 is a plan view illustrating the separator and selector of Figures 9 and 10 incorporated in a stethoscope.

Figure 17 is a detail fragmentary sectional view Figure 21 is a fragmentary sectional view 0 a detail.

Referring at first more particularly to the embodiment of the invention as shown in Figurel, it will be'explained that the device includes'a frequency divider orseparator 5 in the form' of a tapered. truncated or substantially conical hol low body divided by partitions 8 into a plurality of chambers 9,10, ll, etc. so that the separator consists of a series of fluid filled chambers progressively decreasing in diameter from end to end of the series.

end of the series.

Also, the chambers progressively decrease in width from the larger to the smaller. Thus, the cubical volume of the fluid in the chambers progressively, decrease from the larger to the smaller end of the part 5,

and, therefore, it will be understood that the separator includes a succession or series of chambers progressively varying in cubical volume from end to end of the series. Each chamber of the series, known as a resonator, contains a predetermined volume of fluid such as will resonate or mechanically vibrate sympathetically with a predetermined frequency. This frequency is known as the resonating capacity of the particular chamber, i. e., the body of fluid contained therein. Each chamber or resonator will, therefore, selectively receive into its fluid contents through its intake port 52 frequency or rate of vibration which it is designed to receive from the plurality of frequencies contained in the volume of fluid in the parts A, 55 and While it is the volume of fluid in any chamber which resonates rather than the chamber itself, for the purposes of the present disclosure these chambers will be referred to as resonator chambers.

A complex frequency or a plurality of frequencies o'r rates of vibration to be treated and which are contained in a medium such as a fluid, are introduced by the medium into the respective predetermined resonant volume of fluid in each of the resonator chambers of the separator in any suitable manner, as by means of a frequency receiving Or collecting bell A connected by a fluid filled tube 50, of suitable length, and may be rigid or flexible, to the adjacent end of a fluid filled tube 5! extending concentrically through the separator and provided with port openings 52, one for each resonator chamber, whereby frequencies or rates of vibration may be picked up, say from the'body of a person, by the bell and passed through the medium of fluid into the tube 50 to the fluid filled tube 5! from which the frequencies or rates of vibration will pass through theports 52 and into the fluid in the respective resonators in accordance with the capacities thereof whereby the complex frequencies picked up by the bell A are separated into component frequencies in accordance with the predetermined or designed resonating capacities or natural period frequencies of the different resonators composing the separator 5.

Provision is made for selectively taking frequencies from the series of resonator chambers. One way of doing this being shown in Figure 1 wherein there is shown an enlarged view of a fluid filled valve casing 53 suitably secured to the separator 5 longitudinally along one wall thereof, such wall being provided with a series of port openings 55, one for each resonator chamher. That wall of the valve casing 53 which lies against and is secured to the adjacent wall of the separator 5 is provided with a series of port openings 55 registered respectively with the port openings 55 of the several resonator chambers so that frequencies may pass from the resonator chambers into the valve casing. Within the valve casing there is valve mechanism for selectively providing communication between the resonator chambers of the separator and the interior of the valve casing. This means consists of a valve inthe form of an open-ended cylindrical piston divided transversely into two piston sections 55 and 51 mounted to slide endwise within the cylin-' drical valve casing 55 and also to rotate therein and having a working fit with the interior walls of the casing. The inner or adjacent ends of the valve sections abut one another, and these abutting end edges are provided with registered tapered or V-s'hapednotches or slots 55' and 5'1? 50" asto jointly form a triangular valve port opening through the wall of the valve which port is intended to be registered selectively with the ports 54 and 55 whereby to selectively pass frequencies from the resonator chambers into the interior of the piston sleeve valves 56 and 51 and thence through its open ends into the fluid filled valve casing 53. With the valve members 55 and 51 rigidly connected for simultaneous movement, in a manner as will hereinafter be described, the valve may be moved endwise within the valve chamber to selectively register the port of the valve with the ports 55 of the valve casing, in the manner as will now be described.

As illustrated in Figures 2 and 3 of the drawings, the piston sleeve valve sections 56 and 51 are abutted in such a relation that the tapered notches or slots 56' and 51' register and form an isosceles triangle with the base of the triangle extending in the longitudinal axial direction of the valve, the other two sides of the triangle extending obliquely across the valve. In Figure 2, the apex portion of the triangular opening is registered with one of the series of ports 55 in the fluid filled valve casing 53, shown in dotted lines in Figures 2 and 3, so that in this position frequencies may pass from one of the resonators of the separator through the aligned ports 54 and 55 and through the apex portion of the port opening in the valve and into the fluid filled interior of the latter and thence into the fluid filled valve casing 53 from which it may be conducted as will be hereinafter described. By sliding the valve endwise, the apex portion of the triangular valve opening may be selectively moved into registration with any of the series of combined ports 5d and 55 for taking frequencies from any one of the separator resonators as Will be understood.

With the apex portion of the valve port in reg istration with any intermediate port of the separator, as in Figure 2, by rotating the complete Valve on its longitudinal axis,to the right, in Figure 3, the tapered valve port will come into registration with the next adjacent ports of the separator at opposite sides of the port with which the apex portion of the valve port was first in registration, from the separator resonators at opposite sides of and next to the original resonator, whereby there will be a spreading of the band of frequencies re-' ceived from the separator and passed on by the valve to a point of use or consideration. By rotating only one of the valve sections, say 51, as in Figure 4, from the original position as in Figure 2, band spreading may be accomplished at one side only of the frequency received in Figure 2, the original setting of the valve members. Thus, by moving the valve longitudinally and also rotatively, and by separately rotating the valve sections, many valve adjustments and consequent frequency selections may be made.

As illustrated in Figure'l of the drawings, the valve section 55 is open at one end and is provided at its opposite end with a head 58 which may have openings therethrough or be in the nature of a cross head or other shape so that the right hand end of the valve section may not be entirely closed but will be open enough for the passage of frequencies therethrougln A valve stem 59 is suitably secured to the center of the head 58 and extends at right angles therefrom through and beyond the right hand end of the valve casing 53 where it is provided with a suitable knob or handle 65. The valve section-'51 is open at its inner end and is provided at its 'outer end with ahead'lil thereby opening communication tag-521* similarto the head 58. A tubular valve stem 62, embracing the valve stem 59, is secured to the head'BI and extends therefrom to the exterior of the valve casing where it is provided with a knob I or handle 63 lying in close proximity to or in contact with the inner face of the handle 60. By taking hold of both handles 60 and 63, the complete valve may be moved longitudinally in opposite directions within valve casing53i Likewise, the complete valve may be rotated within the valve casing; By manipulating either handle, itsvalve section may be rotatedindependently of the other valve section. Thus, the various adjustments of the valve and its valve sections may be accomplished, as hereinbefore set forth.

One end of the valve casing 53 may be closed in any suitable manner. The outer end of the valvecasing may be closed as by means of a screw cap 64 having a central opening for the passage of the valve stems. One or more openings 65 maybe provided through the head 54, and the head may b'provided with a nipple 66, one for each opening 65; and flexible or other fluid filled tubes, not

shown, may be connected to the nipples to so as to conduct frequencies to any desired place for use or consideration. It will, of course, be understood that this arrangement, as shown in Figure 1, may be greatlyvaried-and illustrates merely one way of conducting frequencies from the valve casing. 1

-For the purpose of accurately adjusting the valve with respect to the port openings of the frequency separator 5, a gauge has been provided for each of the valve sections, as best illustrated in Figure 7 ofthe drawings, wherein 53 designates a fragmentary portion of thevalve casing, and 56 and 57 indicate the abuttedends of the valve sections.- The valve sections are provided with parallel longitudinal gauge lines and transverse gauge lines as indicated. Th valve casing is provided with a sealed window 61 for the valve 5B and a sealed window 68 for the valve 5lwhereby the gauge lines may be readily viewed. Each window is provided with crossed hair 1ines-69 with which the gauge markings may be registered and thereby the valve may be accurately set in the Well known manner.

While; in Figure 1, means is shown for con-- ducting frequencies from one end only of the valve casing, it will, of course, be understood that suitable provision maybe made for conducting frequencies from the opposite end of thecasingifit is desiredto do so.

Provision is made for substantially maintaining a predetermined pressure in the mediumemployed for transmitting theirequencies, usually air,

within the device of thepresent invention. One such means has been shown indetail in Figure-1 of thedrawings. The pressure reliever shown is that of a'casing "l0 suitably secured to the small end of the selector member 5 and surrounding the open adjacent end of the tube orpassage 5 l The inner end of the part 10 is. open, and an elastically yieldable diaphragm is provided withinthe casing 10, covering the inner open end thereof and extending across the open endof the tube 5 I.

out say to the dottedline position thereof, thereby relieving the pressure within the device. A suitable number of vent openings 12 are provided in the casing at the outer side of the diaphragm so as-to perm-it of the necessary movement of the diaphragm. 1 Another form of pressure relieving means shown in Figure 6 wherein a casing l3-- Should pressure build up within the' device,- it will act against the diaphragm 'll and bulge it is secured tothe smaller end of the separator-5 with its inner end in communicationwith the' open end of the tube 5|. Within the casing '13 there is a reciprocatory head or piston 14 lying acrossthe open end of the tube 5 I and subject to 1 the pressure of a spring 15 against its outer face I and the pressure within the device on its oppositeface. Suitable vent openings 16 are provided-in the casing 13 to facilitate the movement of the piston '14 under a change in pressure within the device.

It will be noted that in each form of pressure reliever, the air or other medium carrying fre-' quencies isnot vented to the atmosphere but is retained within the sealed device and so there" is no escape or loss of frequencies due to the action of either of the pressure relievers, and extraneous frequencies cannot pass into the device through either of the pressure'relievers..- r

Thevalve mechanism shown in Figure 1 of the drawings is intended for selecting frequencies and bands of frequencies from the separators-5. However, frequencies'may betaken from the -resonator chambers of the separator without usingthe valve, as frequencies may be individually taken from the resonator chambers by means of valved nipples 11 provided upon the peripheral wall of the separator and communicating with the respective resonator chambers. If desired,

any one or more of thenipples 11 maybe provided, see Figure 21, with means responsive to the frequencies contained in any resonator cham- 1 her, such as a casing 18 having one end closed and provided with a tubular connection 19 threaded or otherwise secured to the outer open end of one of the nipples". Extending across the open end of the casing is a diaphragm which closes the casing against the escape of frequencies into the atmosphere and prevents passage of extraneous frequencies into the sep-( arator. This diaphragm may be associated with any means to be actuated by the vibrations of the diaphragm. Apin -8l carried by thediaphragm at the center thereof may be employed for this purpose in a manneras is well understood. This diaphragm may -be constructed to resonate at the frequencies contained in the res-'- onator chamber to which it maybe attached.

In Figure 8 of the drawings therehas been shown on an enlarged scale a somewhat modified form of the valve mechanism, and in this figure there has been illustrated'a fragmentary portion of the separator 5 which is the same as that hereinbefore described. Secured to the outer periphery of the separator is a valve casing 82 similar to the valve casing. 53 of Figure 1,- and provided with a series of ports 55 registering with the series-of ports 54 in the separator as hereinbefore described. Instead of having the valve divided into sections, there is a single fluid filled tubular sleeve valve 83, one end of which projects beyond the valve casing, which latter is provided with a stufling box 84 through'which The tubular valve is provided with a triangular-valve A port opening 85 as in Figure 1, having its apex arranged for registration selectively with the ports 55 of the valve casing. The tubular valve member is capable of endwise movement and the outer end of the tubular valve Works.

rotative movement for the purpose as described for Figure 1. The externally projecting end of the tubular valve membermay be provided with T 1 any suitable meansrfor leading off frequencies, i as by being provided with acap' 86 havingan open outer end for connection with a micro-;

9 at the smaller end of the separator to limit the endwise movement of the separator under the influence of the spring I9. The stops 24 and 24 may be in the form of nuts threaded on tube I for adjustment thereon.

Normally, the stufling boxes 22 and 23 are adjusted to permit smooth sliding and turning movements of the parts 5 and I while at the same time excluding extraneous frequencies.

When the separator 5 has been moved to any selected position on the tube I, it may be held or locked in such position by tightening one of the stuffing boxes 22 or 23 so as to compress the packing and thus lock said stuifing box and the separator 5 on the tube I in such selected position.

The stuffing boxes 22 and 23 prevent leakage under normal conditions; permit leakage or venting under pressure changes; and constitute looking means or units for holding or looking the separator 5 in any adjusted position on the tube I. I In the adjusted position of the valve part I6 inFigures 9 and 10, the received frequencies are separated into components by the respective resonatorsof the separator 5, while the valve I6 'makes the selection of the frequency to be used .or considered in that such valve I6 closes the port I3 of the resonator 9, and so the frequency which would otherwise pass into resonator 9 is passed on through tube l to a place of use and thus separated from the others. In other words,

the separator part 5 together with either of the slots I 4 and I5, and the valve I6, constitute means for separating the received frequencies into components in that some of the components are separated out by means of the resonators and others are separated by the valve from those separated out by the resonators. That part of the tube I which has the slots liland l5 and the valve I6 constitutes means for selecting the separated frequency or frequencies to be passed on for use. Accordingly, it will be understood that Figures 9 and 10, like Figures 1 and 8, present frequency separating means and means for selecting the separated frequency to be passed for use.

In the embodiment of my invention in a stethoscope, as shown in Figure 16, and with the use of a collapsible bell, as illustrated in Figures 19 and 20 and described in detail in my copending patent application, by placing the bell against the body of a person and pressing against the small end ofthe separator 5, the bell may be selectively collapsed thereby reducing the effective cubical volume of the fluid'in the bell and also the area of the mouth of the bell,'thereby 4 obtaining a relatively coarse frequency selection which willbe conducted by fluid through the tube I into the separator 5. In the separator the frequencies selected by the bell will be more finely separated, and through the use of the valve part I6 any frequency may be selected. Thus, a relatively coarse selection may be made by selec tively collapsing the bell, such selection may be separated into its component parts by the separator 5, and the valve I6 used to make any desired selection from the finely separated frequencies, and such selection conducted by fluid through tube 1.

By proportioning the spring I9 and the resonators in separator 5 with respect to the collapsi- "-bilitypf the bell, and when the separator 5 is moved against the spring so as to progressively collapse the bell against the body of a person, the travel of the separator along the tube I will be in a predetermined relation to the collapsing of the bell and consequently the separator will be automatically positioned on the tube I so as to properly separate the fluid borne frequencies conducted thereto by the bell in its progressively collapsed condition, and the valve part I6 will thus be located to close the resonator corresponding to the desired or selected frequency, and thus said frequency will be conducted through fluid in tube I.

By employing a gauge such as is shown in Figure 7, and indicated at 10 in Figure 16 any predetermined frequency selection may be made by sliding the separator 5 along the tube until the desired marking on the gauge 10 appears through the window thereof.

- The separator 5 may be first set on the tube 23. Then theresonant frequency of the closed resonator will be prevented from entering into said resonator but will be conducted on through the fluid in tube I, while the other frequencies will pass into'and be trapped in their respective resonators of the separator.

-As distinguished from the use of a'rigid bell, when a collapsible bell is used, the collapsing thereof will make a preliminary selection of frequencies, causing a lower intensity of undesirable frequencies to be fluid borne to the separator than when the full size bell isemployed, thereby enhancing the eflicientoperation of the separator and selecting of the desired frequency.

The collapsible bell of -my invention may be made of any elastically yieldable material such as will permit collapsing of the bell for thepurposes of the invention. I contemplate specifically the use of rubber, sponge rubber, any of the synthetic rubber materials, such as neoprene or any other elastic material suitable for the purpose. v

Pressure changes may occur in the use of the present instrument and provision has been made to relieve such pressure changes.

To maintain a constant pressure within the device when in use, as shown in Figure 17, there may be provided in one wall of the tube I a vent opening 29 leading to a vent nipple 30, the inner end of which communicates with the vent opening 29. A screw cap 3i is provided upon the outer open end of the nipple 3E! and is provided with an exhaust vent opening 32. A valve-member 33, preferably in the form of a ball, is contained within the inner portion of the nipple 30 and is normally held against the vent opening 29 to close the same by means of a coil spring 34 bearing at one end against the valve and at the other end against the cap 3|. Under normal conditions and handling of the device,

' the valve 33 is held closed, but should the source an inlet opening 38 in its outer end, which opening is normally closed by means of the valve 39 subject to the pressure of the spring 40 so that when pressure is lowered within the device and having a stem 45 passing through the vent opening and provided at its outer end with a head or button 41, there being a helical spring 48 surrounding the stem and bearing in opposite directions against the inner face of the head AT and the outer end of the cap. In this arrangement the spring maintains the valve closed. The operator by pressing upon the head 41 and compressing the spring, may open the valve 45 whenever desired.

What I claim is:

1. A frequency selector for selecting frequencies from a volume of fluid containing a plurality ofvibrations of different frequencies comprising a frequency separator made up of a plurality of fiuid'filled resonator chambers cfdifferent cubical volumes and resonator capacities, a fiuid filled valve casing having ports communicating with the respective chambers, a tubular open ended valve working within the casing and provided with a triangular valve port for selective registration with the ports of the valve casin said valve being rotatable to bring its p'ort'into registration with a plurality of the ports of'the valve casing.

2. A frequency selector for selecting frequencies from a volume of fluid containing a plurality of vibrations of different frequencies comprising a frequency separator made up of a series of fluid filled resonator chambers of different cubical volumes, a valve casing having ports communicating with the respective chambers, a reciprocator tubular open ended valve working in the casing and divided into two tubular sections provided in their inner ends with tapered openings which when registered provide a triangular valve port for selective registration with the ports of the valve casing, said valve being adjustable endwise within the casing, and said valve sections being independently rotatable within the valve casing.

,3': A frequency selector for selecting frequencies from a volume of fluid containing a plurality of vibrations of different frequencies comprising a frequency separator made up of a plurality of fluid filled resonator chambers of different cubical volumes and resonating capacities, a fluid filled valve casing extending concentrically through the resonator chambers and having ports communicating with the respective chambers, a tubular open ended valve working within the casing and provided with a triangular valve port for selective registration with the ports of the valve casing, said valve and casing being relatively rotatable to bring the triangular port into registration with aplurality of the ports of the valve casing.

4. A frequency selector for selecting frequencies from a volume of fluid containing a plurality of vibrations of difierent frequencies comprising a frequency separator made up of a plurality of fluid filled resonating chambers of different cubical volumes and resonator capacities, a fluid filled valve casing extending concentrically through the chambers and having ports communicating with the respective chambers, a tubular open ended valve movable longitudinally and rotatably within the casing and provided with a pair of longitudinally aligned triangular valve ports for selective registration with the ports of the valve casing, the inner ends of the triangular valve ports being, spaced to provide a valve element in the valve member.

5. A frequency selector for selecting frequencies from a volume of fluid containing a plurality of vibrations of difierent'frequencies comprising a frequencyseparator made up of a plurality of fluid filled resonator chambers of different predetermined cubicalvolumes and resonating capacities, a valve casing extending concentrically through the chambers and having ports communicating with the. respective chambers, a tubalar open ended valve movable. longitudinally and rotatably within the casing and. provided with a triangular port for selective registration with the ports of the valve. casing, a frequency pickup device for receiving a plurality of mechanical vibrations of different frequencies and adjustable for frequency selectivity and connected to one end of the valve member, and ear pieces connected to the other end of the valve member.

6. The herein described method of treating sound vibrations of different frequencies, comprising the steps of receiving-in a confined body of air a plurality of vibrations from a vibrating member, excluding other vibrations from said confined body of air, separating said'confined vibrations into component'vibrations, selecting from said separated components and maintaining a predetermined pressure in the confined body of air.

'7. The herein described method of treating air sound vibrations of different frequencies received. from a vibrating member, comprising receiving said vibrationsin a confined body of air, excluding other vibrations from the confined body of air, individually trapping components of said vibrations while confined, selecting from the trapped vibrations, conducting said vibrations to a point of use, and maintaining a predetermined pressure in the confined body of air. 8. The herein described method of treating vibrations of different frequencies, comprising the steps of receiving in a body of confined air a plurality of such vibrations, individually receiving from the said body of air and trapping vibrations, selecting a. predetermined trapped vibration, conducting said selected vibration to a point of use, and maintaining apredetermined pressure in saidbody of confined air.

WARREN S. EATON.

REFERENCES CITED The following references are of record in the file of this patent? UNITED STATES PATENTS 

